A device, a method and a server for performing device identification of electric appliances connected to a network are provided. An information processing device, to which electric appliances are communicably connected via a network, receives a packet at least containing a packet for checking the status of a communication port of the electric appliance. The information processing device stores definition files defined for each electric appliance in advance, compares the received packet with the definition files for each electric appliance, scores the packet, extracts a definition file with a highest score, and determines a type of the electric appliance from the extracted definition file.